Trees and Sustainable Urban Air Quality in Port Harcourt, Nigeria
Total Page:16
File Type:pdf, Size:1020Kb
FUO Quarterly Journal of Contemporary Research, Volume 6 No. 4, December 2018 TREES AND SUSTAINABLE URBAN AIR QUALITY IN PORT HARCOURT, NIGERIA OJULE, EMMANUEL S.C., Department of Geography and Environmental Studies Faculty of Social Sciences Ignatius Ajuru University of Education Rumuolumeni, P.M.B 5047 Port Harcourt [email protected] CLIFFORD ANARIOCHI B. Department of Geography and Environmental Studies Faculty of Social Sciences Ignatius Ajuru University of Education Rumuolumeni, P.M.B 5047 Port Harcourt [email protected] UKPERE, DENNIS T.R. PhD. Department of Geography and Environmental Studies Faculty of Social Sciences Ignatius Ajuru University of Education Rumuolumeni, P.M.B 5047 Port Harcourt [email protected] ABSTRACT This paper examined the relevance of trees for the promotion of Port Harcourt ecosystem. The paper argued that Port Harcourt as a major urban centre in Nigeria is growing in size and complexity. As a major industrial and commercial city, it is presently experiencing an increase in air and noise pollution. This pollution is a function of two primary factors: increase in the use of fossil fuel by the rapid growth in automobiles and industrial domestic power plants (generators) and growing affluence in the life style of city residents. Thus, there is correspondent increase in traffic, noise and emission of C02 (carbon dioxide) and Co (carbon monoxide). As a result of this, air pollution over Port Harcourt had reached a critical stage and efforts must be made to combat this environmental challenge. The cheapest and clearest way of addressing this problem is by massive planting of trees across the length and breadth of the city. Trees help to remove pollutants especially O3NO2 and VOCs from the air which makes the atmosphere cleaner. The removal of pollutants by trees is a local effects whereas the formation of pollutants from compound emitted by trees occur downward of trees themselves. Thus, the cumulative and interactive effect of trees on pollution removal is an essential part of greener, cleaner and pollution free environment. Keywords: Port Harcourt, Air Pollution, Air Quality, Trees, Urban forestry INTRODUCTION Urban centres are centres of high residential, commercial and industrial activities. One of the environmental problems associated with urban centres is air pollution which Ojule, E.S.C., Clifford A.B. & Ukpere, D.T.R. 251 results to poor air quality. Air pollution occurs when harmful substances including particulates and biological molecules are introduced into Earth’s atmosphere. It may cause disease, allergies or death of humans. It may also cause harm to other living organisms such as animals and food crops and may damage the natural or built environment. Human activity and natural processes can both generate air pollution. Mayhew (2009) defined air pollution as the presence of substances in the air in quantities which can affect animal or plant life, human health and welfare, or can unreasonably interfere with life or property; and that common pollutants include carbon dioxide (CO2), carbon monoxide (CO), lead (lb), nitrogen oxide (NO2), ozone (O3), smoke, and sulphur dioxide (SO2). Air pollution may cause disease, allergies or death of humans; it may also cause harm to other living organisms such as animals and food crops, and may damage the natural or built environment. Human activity and natural processes can both generate air pollution. According to World Pollution Organization (2010) indoor air pollution and poor urban air quality are listed as two of the World’s worst toxic pollution problems in the 2008 Blacksmith Institute World’s Worst Polluted places report. According to the 2014 World Health Organization report, air pollution in 2012 caused deaths around 7million people worldwide an estimate roughly echoed by one from the International Energy Agency (WHO, 2014 and IEA, 2016). Air pollutions all over the world are measured by a method known as Air pollution index (API). Air quality index is a number used by government agencies (International Air quality 2015) to communicate to the public how polluted the air currently is or how polluted it is forecast to become (National Weather Service, 2015). According to Wikipedia, the free encyclopedia, as the air quality increases, an increasingly large percentage of the population is likely to experience increasingly severe adverse health effects (Wikipedia, n.d.). Thus different countries have their own air quality indices, corresponding to different national air quality standards. Some of these are Air quality Health index (Canada) the Air pollution index (Malaysia) and the pollutants standards index (Singapore). Air quality index measurement is between 0-300+ and it is categorized into six sections. The air in a city is rated as follows: 0 to 50 (safe), 51 to 100 (moderate), 101 to 150 (unhealthy for sensitive groups), 151 to 200 (unhealthy), 201 to 300 (very unhealthy) and 301 to 500 (hazardous). A tree is a noble organism, unique in its beauty and home and refuge for birds, insects and small animals. Trees are more than just heavens for animals, birds, insects and humans; they are also the wings of the earth. Just as we do breathe oxygen into our lungs and exhale carbon dioxide, so trees breathe carbon dioxide into their leaves and exhale oxygen. Trees are really upside-down lungs: their trunks are equivalent to the trachea, their branches to the rights and left main bronchi and all their branching twigs and leaves to small bronchi and alveoli, air sacs, where the exchange of oxygen and carbon dioxide takes place. Tree trunks and branches may appear solid, but they are really rigid channels that transmit water and nutrient to the leaves the way the trachea and air passages transmit air to the alveoli. Trees play a significant role in moderating the earth’s climate. They remove carbon dioxide from the atmosphere and store large quantities of carbon in their tissue. Nigeria, like other developing countries in the world is witnessing a significant growth in population size and rate of urbanization especially in the last two decades. According to the Federal Ministry of Environment (2015a) despite this increase, there appears to be imbalance between urban growth and availability of such infrastructure to reduce the impact of urbanization on the environment. The ministry further observed that FUO Quarterly Journal of Contemporary Research, Volume 6 No. 4, December 2018 252 one of the consequences of this imbalance is the emergency of accelerated urban air pollution which is most dominant in emerging potential mega cities in the country. In Nigeria the Federal Ministry of Environment (2015b) opines that Nigeria is among the most intensive atmospheric aerosols in the world and that the two main pollutants and sources in the country are particles from desertic zones of Sahara and biomass burning that constitute huge amount of black and organic carbon; and these account for over 70% of air pollution in the country. The ministry further noted that the sources of this air pollution are associated with combustion from vehicles, domestic power generations and industrial plants. The problem of air pollution in Nigeria has been receiving much attention locally and globally. Not long ago, the World Health Organization (WHO, 2016) listed four Nigerian cities (Onitsha, Kaduna, Aba and Umuahia) among the world’s most polluted cities. According to the report, Onitsha was rated as the world’s most polluted city for air quality when measuring small particulate matter concentration (PM10). Kaduna came fifth in the world and it is a major transport hub in the North; and Aba and Umuahia came sixth and sixteenth respectively. (Uwaegbulam, 2006), both cities are major trade centres in Southern Nigeria. The report explained that “reliance on using solid fuels for cooking, burning waste, and traffic pollution from very old tyres” were contributory factors to the pollution in these cities. To arrive at the ranking, WHO compared a total of 795 cities in 67 countries for levels of small and fine particulate matter (PM10 and PM2.5) during the five year period, which started from 2008 to 2013. This PM10 and PM2.5 include such pollutants as sulphate nitrates and black carbon, which penetrate deep into the lungs and into the cardiovascular system posing the greatest risk to human health (Uwaegbulam, 2006). Data were then analyzed to develop regional trends. PM 2.5 are atmospheric particulate matter (PM) that have a diameter of less than 2.5 micrometers, which is about 3% the diameter of a human air. Particles of this category are so small that they can only be detected with an electron microscope. They are even smaller than their counterpart PM10, which are particles that are 10 micrometers or less, and are also called fine particles. Although Port Harcourt was not mentioned by World Health Organization as one of the cities in Nigeria suffering from air pollution, studies by Sun newspapers (2017), Popoola (n.d), Tamuno (2016), Allen (2017), and Igbenedion (2018), have shown that the city of Port Harcourt is heavily polluted by air pollution and black sooth. According to Igbenedion (2018), the pollution of the air in Port Harcourt has been detected as “unsafe” by a global app used to detect how safe the air is at any location in the world. The app also indicated that the air in the city contains a dangerous substance known as PM 2.5 which can cause cancer and lead to premature death, respiratory illness etc. The app record showed that Port Harcourt city has an air quality index of 190, which is unhealthy. According to the sun newspaper, residents of Port Harcourt and its environs have been battling soot in their homes, offices, and business premises, churches, on vehicles, clothes and food items. The paper further reported that to contain the situation, the state governor, Chief Nyesom Wike set up a task force headed by the Commissioner for Environment, Prof Rosliyn Konya, to investigate and resolve the environmental challenge.